Applications of IASI on MetOp-A : first results and illustration of potential use for meteorology, climate monitoring and atmospheric chemistry

摘要

IASI was successfully launched on MetOP A on 19 October 2006. After the in-orbit commissioning, the performances of IASI were evaluated during the Cal/Val of level 1. Key parameters of instrument and on ground processing have been fixed for optimal performance and best quality data delivery. The first spectra and images of level 1 products show all the potential of IASI data for expected applications. Some illustrations are given here with maps of pseudo channels sensitive to trace gases, atmospheric profiles or maps of surface temperature qualitatively compared to maps from models. Level 2 processing to get these parameters has been implemented at Eumetsat and some products are currently under validation. The quality of IASI data paves the way to additional very promising products. A thorough analysis of cloud free spectra has been performed to extract the small signature of minor species like CFCs and HNO_3. Nevertheless, the main limitation of IASI data remains clouds. It is showed here with the cluster analysis of AVHRR data registered in the IASI pixels and delivered as level 1 products that only a few cloud free pixels can used for full retrieval. A method making use of the cluster information has been developed. It permits to strongly increase the statistics where clear column profiles or columns above clouds can be retrieved. This scheme will be applied to the retrieval of the CO_2 where large data set are needed to extract information from the spectra.